The present invention generally relates to primary batteries and more particularly to a sea water battery having a high energy density. The device is uniquely applicable for use on underwater vehicles.
Development efforts for the last generation have resulted in a sea water battery having a silver chloride or silver oxide cathode and a magnesium or aluminum anode. Improvements to the battery have resulted from improved anodes and enrichment of electrolytes. However, prior to the present invention there has been no improvement for the silver chloride or silver oxide cathode. Battery capacity has been limited by the maximum thickness and density of the solid cathode. As the cathode discharged, performance deteriorated since the electrolyte had to travel through the pores of the reduced silver. In addition, the cost of silver has increased enormously. The anode, on the other hand, could be kept clean by acid in the sea water. This plus major improvements in power density and anode efficiency serve to further emphasize the limitations of the cathode.